are managers rely needed ?

Not as much as some people will have you believe

Evidence to that effect has just been realized with one of if not the supposedley best manager in the World being Sacked which I know has completely flabbergasted the pundits, let me tell you the answer isn't rocket science, a managers effectiveness to a teams performance is limited and no matter how good people percieve them to be , they are always restriced by the ability and performances of his players, his reputation and results are really at the mercy of what his players do on the pitch

This means that a Manager can possibly help any respective player to improve, but this effect is going to be limited by the players ability and talent, and how much effort they put in, which means their effect is likely to be directly related to the quality of player they havs at their disposal Ie Top managers tend to remain at the top because they have top players, try reversing that logic and the results won't be the same

Like Gordan Strachen once said iin reply to this statement, You team is stronger on paper so you are confident of a result

Strachen " Well Football isn't played on paper it's played on grass"

Of course.

Managers are the ones who tells the players who they should play (play defensively, ofensive, if they should play with lots of possesion etc..)

It teaches how the players should be positioned, their instrutions

Example: An instruction could be the 2 Center Backs need to stay back while attack. Or the Striker should help in the defensive labour during the match etc...

Without managers the team could be able to play but would not have a clear reference on how to play

personally I don't think managers are needed for sport or business they are only as good as the team or workforce a good experienced trainer already in sport and workplace dose more than a Manager as for the office well my wife is an assistant to the manager but she runs everything and one is sure this is true for most business this is probably why when I think of it all you need is trainers secretaries so lets get rid of managers and share what is often a HIGH SALARY which they don't earn and give it to the workers who earn it

Do you guys call them manager in england?

Not when you have players like messi, neymar and Suarez in your squad.

Guardiola is overrated. I'd like to see him coach deportivo or racing.

I don't think there really needed.

sure